Chalcopyrite-driven enhancement of arsenopyrite oxidation in SR-AOPs: The synergistic role of chalcopyrite in free radical propagation and its catalyzation on arsenopyrite oxidation in SR-AOPs

Arsenopyrite, as the main carrier of precious metals and a companion mineral of sulfide ores, needs to be removed in advance before entering the metallurgy process to reduce its impact. The catalytic role of chalcopyrite in enhancing arsenopyrite oxidation under sulfate radical-based advanced oxidation processes (SR-AOPs) was systematically investigated. Through multi-scale characterization (XRD, SEM-EDS, XPS, FTIR, Tof-SIMS, EPR) and electrochemical analysis (OCP, CV, Tafel), this study demonstrates that chalcopyrite significantly accelerates arsenopyrite oxidation. Electrochemical analysis indicates that Chpy optimizes the electron transfer pathway and accelerates the oxidation process of pyrite. Surface analysis identified α-FeOOH/As–O oxide layers and Cu-As/S complexes as critical intermediates. The EPR and quenching experiments demonstrated that multiple activation pathways of chalcopyrite effectively promoted the free radical conversion rate of PDS and enhanced the oxidation efficiency of arsenopyrite. These findings provide mechanistic insights into chalcopyrite-driven arsenopyrite oxidation, offering a sustainable strategy for arsenic removal with reduced reagent consumption.